Adding plusminus to calulator as a variable

[akumaxkun]

Hey guys,

Im making a calculator right now and the only thing i have left to put in is the +/- function.

My teacher does not want us to use:

lblOutput.caption = lblOutput.caption - (lblOutput.caption * 2)

Rather, she wants us to use variables to be able to make a number +/-.

I've run out of ideas on how to do that.

Please help!

Thanks!